Bug#802497: prepair: Fails to build with GDAL 2.0

[Sebastiaan Couwenberg]

Control: tags -1 patch

I've patched prepair to build successfully with GDAL 2.0 as
mentioned in the upstream bug report:

 https://github.com/tudelft3d/prepair/pull/23

The patch is included in the package available in git:

 https://anonscm.debian.org/cgit/pkg-grass/prepair.git/commit/?id=e1c8e5755a4118c7b03aeaf7bc93d9084b955bca

I'm waiting for feedback from upstream before uploading a new prepair
revision with this patch.